The objective of this project is to examine the impact of STD and pregnancy risks on fertility-related sexual and contraceptive behavior of black male and female adolescence and young adult clients of two inner-city STD clinics. These clients are a population at particularly high risk for both STD and unintended pregnancy. Aims are: 1) to describe sexual practice and contraceptive use patterns in this population; 2) to compare effects of theoretically-identified predictors on sexual and contraceptive practice intentions at baseline; 3) to compare effects of predictors, including practice intentions, on behavior to prevent STDs and pregnancy over time. Conceptual framework and hypotheses for this study are based on a modified version of the Health Belief Model incorporating recent theoretical and empirical work on decision making processes. A case-series of 1100 clients (under 30, black, presenting for a new STD episode) will be enrolled over a 5-month period. The study design consists of a baseline interview to determine attitudes and beliefs regarding STDs and pregnancy, interpersonal influences, and background data, as well as sexual and contraceptive practice intentions and two. followup interviews (ac 3 and 6 month intervals) to identify changes in attitudes and beliefs, to identify intervening influences (interpersonal and other) that may have modified attitudes and practice intentions, and to determine sexual and contraceptive behavior during the followup intervals. An initial phase of ethnographic study of 30 clinic clients will inform the development of research instruments and contribute to the interpretation of results. Data analysis will employ multivariate techniques selection of linear, log, or logistic regression will depend on the distribution of the dependent variable. Proportional hazard methods may be used to rake advantage of "event history" data collected in the followup interviews. This study will contribute to the knowledge on which intervention to change behaviors that contribute to STD and pregnancy risks depends.